控制随机数生成概率的一种解决方法 random()

 

var id=null;
var random= Math.random();

if(random< 0.1)
 id= 0;
else if(random< 0.3)
    id= 1;
else if(random< 0.35)
    id= 2;

else if(random< 0.65)
    id = 3

else if(random< 0.7)
    id = 4;

else if(random< 0.75)
 id= 5;

else if(random< 0.8)
  id= 6;

else if(random< 0.9)
id= 7;

else if(random< 0.95)
id= 8;

else if(random< 1)
 id= 9;


alert(id)

 当0<=random<0.1(区间跨度0.1)             id = 0;

当0.1<=random<0.3(区间跨度0.2)            id = 1;

当0.3<=random<0.35(区间跨度0.05)      id = 2;

当0.35<=random<0.65(区间跨度0.3)        id = 3;

当0.65<=random<0.7(区间跨度0.05)       id = 4;

当0.7<=random<0.75(区间跨度0.05)       id = 5;

当0.75<=random<0.8(区间跨度0.05)       id = 6

当0.8<=random<0.9(区间跨度0.1)           id = 7

当0.9<=random<0.95(区间跨度0.05)     id = 8

当0.95<=random<1(区间跨度0.05)         id =9